Mars Plans Advance (and Occasionally Fade)

Mars has the twin attributes of being close by (at least by solar system standards) and retaining a record of its earliest epoch (lost on Earth) when life might have formed. These have made it a popular destination with five orbiters currently operating around it and two rovers driving across its sands. At least as many new missions are in various stages of development or are proposal, ranging from hardware headed for the launch pad in a few months to some that eventually may prove to be no more than vaporware.

In the last two months, there has been significant news about the European-Russian 2018 mission and about NASA’s 2020 rover. NASA also has announced that it would like to send a new orbiter to the Red Planet in the early 2020s. These announcements will be the meat of this blog post, but first I’ll quickly run through the status of other planned and proposed missions.

Six craft to launch as four missions are firmly in development and have fully funded budgets. Europe’s Trace Gas Orbiter and its Schiaparelli technology demonstration lander are in assembly and on track to launch next January. NASA’s InSight geophysical lander is also in assembly for its launch next March, although the mission’s principal investigator reports that the schedule is tight. Design of the 2018 ExoMars European rover and Russian lander are on track, as is NASA’s 2020 rover.

NASA

Artist’s concept of Mars Icebreaker Life spacecraft

It’s likely that another mission to return to the Martian northern polar plains has been proposed for the NASA Discovery program. The Phoenix lander explored these regions, but was frustrated by clumpy soils that made it difficult to deliver samples to its instruments. What the Phoenix spacecraft did find was a layer of ice just below the surface dust that could provide a habitat for life. The proposed Icebreaker mission would follow up on the Phoenix mission with a sampling system that would drill well into the ice and is designed to work with the clumpy soil. The lander, which would be a near copy of the Phoenix and InSight landers, would carry new instruments that would search for signs of life. While this proposal has received considerable publicity, I haven’t heard whether it was actually proposed. Sometimes, proposers learn as they develop their plans that their missions would not fit within the tight budgets of Discovery missions. (I’ve heard of one proposal that I was excited about that wasn’t submitted for the current Discovery selection for this reason.) If the Icebreaker mission was proposed and is selected (beating out 27 other proposals), it would launch in 2021.

China announced plans a few months ago for its own Martian rover mission to launch in 2020. More recently, a Chinese official stated that the budget for this mission was unlikely to be approved in time for a 2020 launch.

There have also been press accounts that India is considering a second Mars mission that might be an orbiter and/or a lander. I haven’t heard whether the budget for a follow on mission has been approved or not.

And now on to the major announcements of the last couple of months.

The 2018 ExoMars mission will use a Russian landing system and platform to deliver a European rover to the surface. Russia has planned to use the landing platform as a scientific station after the rover rolls off it. Until recently, I’ve been unable to find any details about the planned experiments. Now an announcement of opportunity has been issued for European scientists to contribute to Russian-led instruments and to propose their own additions (see here).

Russian Academy of Science Space Research Institute

2018 ExoMars rover and landing stage

The Russian landing stage and long term science station with the European rover on top prior to its deployment.

The documents state that the priorities for the stations are:

“Priority 1:

• Context imaging;

• Long-term climate monitoring and atmospheric investigations.

Priority 2:

• Studies of subsurface water distribution at the landing site;

• Atmosphere/surface exchange;

• Monitoring of the radiation environment

• Geophysical investigations of Mars’ internal structure.”

The documents lists the names only for an ambitious suite of instruments, although it’s not always clear what instruments are already firmly planned versus those that might be added by European scientists. The instruments break down into several groups:

This suite would be a highly capable science station. For example, the station will monitor both the physical state of the atmosphere (temperature, pressure, dust load, etc.) as well has changes in its composition (presumably with a focus on changes in trace gases to provide ground truth measurements for the 2016 Trace Gas Orbiter). The listed target weight for the seismometer suggests a simpler instrument than the InSight lander will carry. Having a second seismometer would help geophysicists narrow down the source locations of Mars quakes. The sensitivity of this new seismometer may be limited if there isn’t a way to lower it to the ground to isolate it from the vibrations within the station.

What I am surprised by is that the call for instruments includes requests for significant pieces of hardware to be supplied by European scientists for Russian-led instruments. In terms of instrument and spacecraft development, 2018 is practically around the corner. I will be interested to see how the Russians and Europeans manage the selection, development, testing, and integration of these instruments in this short time frame. Perhaps considerable work has already been done or there are flight-ready designs already available.

Two years after the ExoMars station and rover arrive, NASA will land its 2020 rover. The rover itself will be a near copy of the Curiosity rover currently on Mars, but with a next generation instrument suite. A major new goal will be to select and cache a suite of samples that a later mission might collect and return to Earth.

NASA / JPL-Caltech

2020 NASA Mars rover concept drawing

Each sample will be about the size of a stubby pencil. Previously, NASA had planned to put each sample into a canister as it was collected. This canister would then be placed on the surface for later collection after it was full. But recently, there has been a major change proposed for how these samples will be cached (see here).

The original plan had two key limitations. First, as the canister acquired more and more samples, it would become an increasingly precious resource. This would lead the mission’s operators to become increasingly conservative in their operation of the rover. Should they, for example, explore an interesting looking ridge, but one where if the rover fails the rock face would prevent a future mission from being able to reach the canister? Second, there was no good way to remove samples once they were in the canister. What if the canister was full and then scientists find the one sample they absolutely want to collect for return to Earth?

In the new plan, dubbed the Adaptable Cache, the rover would still drill out samples and put them into sample tubes. Then instead of putting the tubes into a canister, the rover would place them on the surface and then move on. A future sample return mission would carry a rover that would pick up the samples and place them into a canister it carries. This way the 2020 rover can cache more samples than could be returned and scientists would send the subsequent rover to pick up only the most important ones. Even with the old scheme where the 2020 rover carried the canister, the follow on mission would still need a rover to fetch the canister. Now that follow on rover would need a more capable arm to pick up tubes lying on the surface and place them into its own canister.

The new rover will also have an upgrade to its engineering cameras. On Curiosity, the navcam/hazcam cameras used to operate the rover take black and white images. The 2020 rover will carry color cameras that will take higher resolution images. Curiosity carried just one camera to record its descent and landing, placed on the bottom of the rover to look down. The 2020 rover will carry additional cameras that will look up at the descent stage that carries the descent rockets, a camera on the descent stage looking down at the rover, and a final camera on the backshell to image the parachute opening.

With these new cameras, being an armchair explorer of Mars will get, as they say, a whole lot better.

In one other item of Mars 2020 rover news, the current cost estimates for the mission appear to be in the $2.14–$2.35 billion range instead of the previously quoted $1.5 billion. A reasonable portion of this increase likely comes from the new figures representing inflation through launch and operations, while the original cost estimates were, I’m told, were in 2015 dollars. At the new figures, the 2020 mission, given inflation, still will be considerably cheaper than the Curiosity mission on which much of the design will be based.

The final major news for Mars exploration was NASA’s announcement that it would like to fly a new orbiter to Mars in the early 2020s (see here). NASA will need a new orbiter to act as a communications relay for future lander missions (such as a sample return fetch mission). The agency could fly a fairly simple orbiter to do just this task. Instead the agency is considering flying a highly capable orbiter that would use solar electric propulsion (SEP).

NASA

Mars 2022 orbiter

NASA is considering a range of options for an early 2020s orbiter to replace the Mars Reconnaissance Orbiter (MRO) currently at Mars. At a minimum, the new orbiter would act as a communications relay for future landed missions. In the most expansive scenario, the new orbiter would carry a much larger payload than any spacecraft has done in the past to Mars.

All previous Mars missions have used rockets to enter Mars orbit. Solar electric engines, such as those used by the Dawn and Hayabusa2 missions, provide a great deal more cumulative thrust. By using SEP, the new orbiter could spiral into Martian orbit. At it lowers its orbit, it could rendezvous with each of Mars’ tiny moons for in-depth studies. Then the orbiter could switch from a near equatorial orbit (where the moons are) to a polar orbit to allow it to study the entire Martian surface.

NASA’s Mars program manager stated that the agency would like to have the orbiter carry a substantial scientific payload (one chart lists a capability to host up to 300 kg of instruments, which would be a very substantial payload). The agency has not stated a preference for what types of instruments – a future scientific definition team would make those recommendations. However, we can do some informed speculation.

In the 2000s, two scientific definition teams looked at science that then future orbiters could make. The highest priority measurements would be to study the upper atmosphere and trace gases in the atmosphere. Time has moved on, and the MAVEN orbiter is at Mars studying the upper atmosphere and the 2016 European-Russian orbiter will study trace gases.

The panels in the 2000s did recommend that future orbiters carry high resolution cameras to image possible landing sites and carry out scientific imaging. Since the mid-2000s, the HiRISE camera on the Mars Reconnaissance orbiter has been imaging the planet at 25 to 32 cm pixel resolution. The HiRISE team described a possible future instrument that would use the same optics, but would provide color imaging across the entire image. (See here.) (The current HiRISE camera has color only for the center fifth of each image.) A future camera also could add imaging in spectral bands in the near infrared that would allow studies of surface composition at high resolution. This future camera could also acquire stereo images to allow 3D analysis of each scene.

Another concept for a future high resolution camera comes from Malin Space Science Systems, who has built cameras for several Mars missions. (See here.) This camera would carry a bigger telescope than HiRISE camera, and the orbiter would fly closer to the planet—skimming just above the top of the atmosphere at perihelion—to acquire images at 5 to 10 cm pixel resolution. This finer resolution would allow more detailed scientific studies of surface features, such as the fine sedimentary bands that are often almost visible in current HiRISE images. (The published abstract for this proposal doesn’t discuss whether the camera would image in multiple color bands. It also doesn’t say how narrow the image strips would be. HiRISE’s lower resolution likely would provide wider image strips.)

Another proposal suggested that a future mission might carry a suite of radar instruments and laser to map the surface and subsurface in detail. (See here.) Ground penetrating radar instruments are already at Mars mapping the subsurface stratigraphy. However, their capabilities are limited by the power and mass available to them within the overall suite of instruments the orbiters carried. The proposal suggests that a future orbiter carry one radar optimized for subsurface stratigraphy and a second for surface mapping that would be able to penetrate the sand and dust that covers much of the planet to image the rock structures below. The proposal also recommended flying a new generation Laser Ranging and Detection (LiDAR) instrument that would remap the altimetry of the surface at much higher resolution. A new orbiter such as the one NASA is discussing would have the power and payload mass to optimize instruments such as these along with a high resolution camera.

Another key capability of the proposed orbiter is that it would use laser optical communication to return data to Earth as well as newer generation radio systems (Ka band). The limit on how much data past and current orbiters have been able to return has not been the instruments, but instead the bottleneck of the communications system. High resolution cameras and radar instruments want to be data hogs, and a new generation orbiter with advanced communication could be an enabling technology to map much larger areas of the planet at high resolution.

This orbiter has just been discussed publicly as a concept for the first time in the last couple of months. None of NASA’s scientific panels have looked into missions past 2020. They may recommend another mission instead. It’s also not clear where the money for the mission would come from. NASA’s planetary program will be funding the development of the $2 billion-ish Europa mission in the early 2020s. If the agency also wants to continue developing a mixture of the smaller Discovery and New Frontiers missions in the same time frame, a major new Mars orbiter may stretch the budget. A next generation Mars orbiter would provide new instrument eyes to study the fourth planet. We will need to wait and see whether the programmatic priorities and budgets line up to enable it to fly.

Comments & Sharing

14

Comments

Arbitrary: 2015/05/09 05:59 CDT

I don't think that a Mars communication relay orbiter can be usefully combined with a surface reconnaissance orbiter. A com sat must be on a much higher altitude than a recon sat. The two functions cannot be combined in the same orbit. So there must be TWO proposed missions mixed up here, not one Telecom/Recon.
Today, Odyssey at almost 4,000 km altitude takes care of the com function, because it has much of a hemisphere of Mars in sight at any time and thus has good coverage of the rovers. And MRO at 300 km altitude does great recon. But it rarely has any rover in sight, and then only during a short window. Plus that it spends almost half of its time behind Mars as seen from Earth.
One hemisphere should be decided to be the priority one for Mars landings during the next couple of decades, and a com sat in Mars "geo"stationary orbit be invested in to cover that hemisphere for 24/7 coverage (or 25/7 as it is on Mars). All this unrelated to recon sats which should be in as low orbits as possible.
Optical communication has been tried from the Moon. But could that really fly as a multi-mission crucial component to depend on, already in 2022 and work from Mars which is 100,000 to 1,000,000 times further away than the Moon?

Arbitrary: 2015/05/09 06:21 CDT

Correction to my note above:
The numbers in the last line are a factor a thousand off. I blame my chaotic re-editings which I didn't review until entered. Mars is of course about 100-1000 times further away from Earth than the Moon is.

Paul F: 2015/05/09 08:04 CDT

Arbitrary,
Mars Odyssey is only several hundred km above the Martian surface, similar to MRO. It's overflights of the rovers lasts minutes, and is very similar to MROs. Both spacecraft have admirably provided both as communication relay satellites and performed years of surface observations.
The current crop of Discovery proposals may prove the optical comm past lunar distances since NASA was providing incentives to the submitters to add the capability.

Arbitrary: 2015/05/10 06:20 CDT

@Paul F
If so, this Wikipedia page needs a correction, it says Odyssey has a 3,750 km altitude:
https://en.wikipedia.org/wiki/2001_Mars_Odyssey
And if so, then I need a teaching in geometry. Everyone around here have a feeling of how much (or little) of Earth is seen from the International Space Station at any given moment. And that you only rarely have line-of-sight contact with it. This is the curse of spy satellites. The informed enemy knows when they are watching (they are satellites in plain sight following Keplerian orbits, their schedule is as reliable as a calendar), and then perform whatever masquerade to misinform the surveillor.
If you relied on an ISS kind of low orbit for communication, then you would not be able to read this. Nor get much data at all from a rover on Mars. I think that the MRO communication with Curiosity, if any, was just a one time off technology demonstration for a desperate backup plan which would eliminate the transmission of basically all images from Mars. It would be huge waste of scientific potential to have the MRO orbit over Curiosity once every period, instead of mapping the entire planet. The 175 km orbit mentioned in the (Malin camera?) paper above is less than half that of the ISS, and Mars has only half the diameter, so the field of view would be even much smaller.
The communication satellites which we actually use in our everyday life, instead orbit 100 times further away from the ISS, 10% of the distance to the Moon, in geostationary orbit. A Recon+Com mission for the price of one? That will hopefully not happen, or it would be a very poor performer in one or both of those functions.
Please feel free to correct me where I'm wrong. I'm at least confident that we all can agree on beaming lasers from Mars would be sooo cool!

PaulF: 2015/05/10 10:52 CDT

Arbitrary,
The Wikipedia article is correct. It is referring to the semi-major axis of Odyssey, not the altitude above the surface. For reference, Mars has a radius of about 3400 km and a hypothetical satellite skimming the surface in a circular orbit would have a semi-major axis of 3400 km. Odyssey's semi-major axis of 3785 km, puts it at several hundred km in altitude.
When Spirit and Opportunity were designed, they were originally planning to communicate primarily using the rover's own direct radio link to Earth and the relay via Odyssey (and MGS) was viewed as of secondary utility for returning the bulk of the mission data. However, the high data rate of having a close satellite (vs. the much lower rate getting the signal to the Earth), meant that even the relatively brief over-flights of Odyssey were useful and eventually became the primary means of communication. With the lesson learned, the more recent rover, Curiosity, was designed so that the UHF relay links to MRO and Odyssey would do the bulk of the data transmission to and from the Earth.
The orbit of both Odyssey and MRO were driven primarily by science requirements. An orbiter truly dedicated to being a relay satellite might indeed have a higher orbit, perhaps even a synchronous one. But even that has tradeoffs - you gain time for the duration of each pass, but you have a weaker link and therefore lower data rate. You also must accept fewer passes per day, or, in the stationary case, you can only service a rover(s) on one side of the planet.

Atom: 2015/05/11 12:08 CDT

It is always time to celebrate whenever NASA chooses a new planetary mission however of late the "economy" class missions (Discovery and Mars Scout) have been dominated by Mars missions. Starting with Mars Phoenix there have been three Mars (Pheonix, Maven and Insite)and two elsewhere missions (Dawn and Grail) If NASA's announced 2022 Mars orbiter is the next Discovery mission chosen, then the program should forgo all pretenses and be renamed Mars Discovery program.
I personally am routing for a mission to another destination. Time will tell.

Torbjorn Larsson: 2015/05/11 06:33 CDT

I find the US planetary science program balanced against stated priorities. Mars is both important (for reasons van Kane mentioned) and close which translates to cheaper and faster science & technology turnaround.
[Really. Curiosity may have nabbed two putative fossils, the MISS candidates described in Astrobiology, and the fatty acid potential detection mentioned at LPSC-15 - I can't find any reports of an actually observed abiotic pathway to those, though Fisher-Tropsch reactions and later hydrolysis may theoretically make them.
People should go up in flames over the potential and demand much more Mars resources. Alas, the Viking experience is a put off I guess.]

Arbitrary: 2015/05/11 09:57 CDT

I think it is good to explore one planet thoroughly. But NASA needs to constantly have an orbiter at an outer planet, and they won't have that during a couple of decades after Cassini. That is a big mistake which will come back to haunt NASA! When the first exoplanetary atmospheres of mini-Neptunes will be examined, no science will be done about our own Neptune. Planetary probes and space telescopes are NASA's success story. As an organization whose HSF programme is criticized, not without good reasons, they need to hold on to their strengths in order to survive (and get a crewed lunar lander or abolish HSF completely, for X's sake!)
@Torbjorn Larsson Really? Astrobiology Magazine? I can't even find their website now.

Arbitrary: 2015/05/11 10:11 CDT

I don't think a stationary drill is a good idea. If it is mobile it could drill at multiple places and even more important, at the right places of interest. Especially after the first few holes when there's enough data to pose the right questions. Rather wait two years more to accumulate the extra funding for it.
I'm surprised that a large fraction of proposals for Mars exploration missions don't seem to be very well thought out, considering the very high quality of the engineering and science.

Dr Morbius: 2015/05/11 08:55 CDT

The caching for sample return does not seem like a very good idea. It would be two years, at least, and probably 6-10 years before a followup mission could be flow, if ever. By that time cosmic rays would degrade the organics in the samples obviating the purpose of the mission.
The problem is the darn Moxie, the ridiculous O2 generating stunt foisting on the mission by Manned Directorate at NASA. It bumped the SAM-2 mass-spec/gas chromo that would have been able to
analyze the samples in place.

Arbitrary: 2015/05/12 05:09 CDT

@Dr Morbius But the drill cores will only be about 1 decimeter deep. They have been bombarded since billions of years, and they could be as well protected on the rover as in the ground.
I agree that the ISRU demo won't give any science return, and no one seems to expect it to fail. I mean, it is not advanced chemistry which has to be demonstrated to be believed (and it could instead have been tested in a lab on Earth which simulates Mars atmosphere). It is a flirt with the loud Mars HSF enthusiast community. NASA wants to demonstrate a strategy for sustainable exploration of Mars with ISRU and where each mission build upon the previous, traumatised by the sudden end of Apollo. There's obviously history, PR and policy involved, but that's the reality NASA lives in.

Enzo: 2015/05/12 11:19 CDT

@Atom,
"however of late the "economy" class missions (Discovery and Mars Scout) have been dominated by Mars missions"
If only it was just the economy class : Curiosity + MSL-2 = $4B :-(

Freewill: 2015/05/31 10:17 CDT

personally I find it really disappointing that there is still no plan on the books to do an experiment to actually test for life.
Even if it gave negative or inconcusive results the data could be important to refining the search before humans arrive.
If life is what we realy care about then we need to start having an experiment to test for it in one way or another on all our missions

alfredsimpson: 2016/03/13 10:01 CDT

Is a mars launch from the lunar surface or near lunar orbit feasible?
Here are some of my thoughts on the matter.
http://totemconsulting.ca/mars.html